Ensuring of the aeroelastic stability of maneuverable unmanned aircraft at the stage of preliminary design

Аuthors

Nedelin V. G.^1*, Parafes S. G.^2**

1. Dolgoprudny Research and Product Enteprise, DNPP, Sobina Av, 1, Dolgoprudny, 141700, Russia
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: nedelinv@rambler.ru
**e-mail: s.parafes@mail.ru

Abstract

One of the most important problems of the maneuverable unmanned aircraft designing is a security from a flutter and aeroelastic stability with the help of automatic control system (ACS). The aeroelastic interaction between unmanned aircraft and ACS can be presented in the form of a multiply-connected loop. There are two line feedbacks in this loop: through the malleability of the actuator and the control loop. This structure indicates that in addition to the flutter the stability losses in the system «actuator– rudder» and in the loop «elastic aircraft– ACS» are possible. The problems associated with stability of the multiply-connected loop «elastic aircraft– ACS» should be considered at the stage of preliminary design. Detection of the oscillations presence fact in the multiply-connected loop only in the design final stages (the laboratory and the flight tests) leads in significant additional to great money costs and time consuming to eliminate undertaken measures. In this paper the iterative approach for solution to the problem of ensuring of maneuverable unmanned aircraft aeroelastic stability at the stage of preliminary design is considered. The approach includes three stages. The first stage is the choice of the structure and main parameters of aircraft circuit stabilization from the view pointof its regarded aeroelastic characteristics. The second stage is subsystems rational individual design: the air frame and the ACS (including stabilization system and actuator). The third stage – the harmonization of the structure and parameters of the airframe and ACS with the purpose of safety requirements satisfaction for the flutter and aeroelastic stability with the help of ACS.

1. There are developed with the purpose of proposed approach implementation
 — mathematical models of stability of the system “actuator – rudder” and the loop “elastic aircraft – ACS”;
- coordination methods for parameters of constructive-technological solution to the airframe and ACS (the actuator and stabilization systems) with the viewpoint of requirements compliance of the aircraft aeroelastic stability.
2. An example of solution to the problem of airframeand ACS parameters coordination with the related requirements to aeroelastic stability is shown. The example illustrates the possible recommendations for ensure of aircraft aeroelastic stability with the help of ACS.

Keywords:

unmanned aerial vehicle, design, automatic control system, flutter, aeroelastic stability

References

1. Afanasev P. P., Golubev I. S., Levochkin S. B, Novikov V. N., Parafes S. G., Pestov M. D., Turkin I. K.. Bespilotnye letatelnye apparaty. Osnovy ustrojstva i funkcionirovaniya (Unmanned aircraft vehicles. Bases of the organization and functioning), Moscow, MAI, 2010, 654 p.
2. Parafes S. G. Elektronnyj zhurnal “Trudy MAI”, 2011, no.49, available at: http://www.mai.ru/science/trudy/published.php?ID=29685(accessed 27.XII. 2011)
3. Parafes S. G. Metody strukturno-parametricheskoj optimizacii konstrukcii bespilotnyx letatelnyx apparatov (Methods of structural and parametric optimization of design of unmanned aerial vehicles), Moscow, MAI-PRINT, 2009, 316 p.
4. Obrazcov I. F., Bulychev L. A., Vasilev V. V. Stroitelnaya mexanika letatelnyx apparatov (Construction mechanics of aircrafts), Moscow, Mashinostroenie, 1986,536 p.
5. Gamynin N. S., Karev V. I., Potapov A. M., Selivanov A. M. Gidravlicheskie privody letatelnyh apparatov (Hydraulic drives of aircraft), Moscow, Mashinostroenie, 1992, p.368.
6. Chashhin V. A., Kamladze O. G., Kondratev A. B. pod red. Chashhina V. A.. Pnevmoprivod system upravleniya letatelnyh apparatov (Pneumatic control systems of aircrafts), Moscow, Mashinostroenie, 1987, p.248.
7. Polkovnikov V. A., Petrov B. I., Popov B. N. Elektroprivod letatelnyx apparatov (Electric drive of aircraft), Moscow, Mashinostroenie, 1990, p.352.

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